Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Net loss	$ (4,740)	$ (19,359)	$ (22,016)	$ (42,046)
Net loss attributable to noncontrolling interest	0	(36)	0	(80)
Net loss attributable to Cohu	(4,740)	(19,323)	(22,016)	(41,966)
Foreign currency translation adjustments	1,897	3,684	968	(1,578)
Adjustments related to postretirement benefits	0	(39)	0	435
Other comprehensive income (loss), net of tax	1,897	3,645	968	(1,143)
Other comprehensive loss attributable to noncontrolling interest	0	0	0	(4)
Other comprehensive income (loss) attributable to Cohu	1,897	3,645	968	(1,139)
Comprehensive loss	(2,843)	(15,714)	(21,048)	(43,189)
Comprehensive loss attributable to noncontrolling interest	0	(36)	0	(84)
Comprehensive loss attributable to Cohu	$ (2,843)	$ (15,678)	$ (21,048)	$ (43,105)